1. Field of the Invention
This invention relates to surface finishing tools. The invention relates more particularly to an improved, portable hand held electriclly energized surface finishing tool.
2. Description of the Prior Art
Among the various surface finishing operations, those typically performed by tradesmen, craftsmen, and homeowners include rotary finishing with peripherally acting finishing devices, such as wire wheel brushes, flexible flap sanding wheels, flexible drum sanders, and cotton buffing wheels. Surface finishing is also practiced utilizing, for example, sanding discs and polishing bonnets. In the latter case, a realtively larger rotary surface performs the finishing.
These finishing devices have in the past been mounted on an output spindle of a stationary drive, or alternatively, they have been rendered portable as accessory devices for mounting in a portable, electric, power drill chuck or in a portable finishing tool. The drill mounted accessories have exhibited various deficiencies including poor handling performance since the use of the accessory is auxiliary to the principal design for axial drilling with a mounted drill bit chuck. Overall handling of the tool is relatively poor because of a relatively large overhang of the accessory device with respect to the axis of the drill chuck. The resultant forces acting on the user have a tendency to fatique the user. From a performance viewpoint, the finishing characteristics are relatively poor since the speed-torque characteristic of the device is not particularly selected to satisfactorily power a variety of surface finishing devices. Moreover, the use of these auxiliary devices with electric drills is done in the absence of safety guards. Some portable power tools have been designed to provide for sanding or for polishing but such tools, which are dedicated to finishing in a plane, provide a direct drive which increases the weight and cost of the finishing tool. Some of these deficiencies can be corrected by mounting the device on a stationary motor but the application is then limited to those jobs which can be hand held.